JP2021030691A - Ultraviolet protective agent, and laminate having ultraviolet protective layer using the same - Google Patents

Abstract

To provide an ultraviolet protective agent that can protect a substrate from ultraviolet rays having a relatively long wavelength, without yellowing an object to which the agent is added.SOLUTION: A laminate includes a substrate and an ultraviolet protective layer. The ultraviolet protective layer includes core-shell type inorganic nanoparticles, an organic ultraviolet absorbent, and a binder. The core-shell type inorganic nanoparticle includes a core part containing zinc oxide or titanium oxide, and a shell part containing silicon dioxide. The chromaticity b* in the Lab color system of the ultraviolet protective layer is lower than the chromaticity b* of a layer that has been formed in the same manner except that the nanoparticles of zinc oxide or titanium oxide are used in place of the core-shell type inorganic nanoparticles.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to an ultraviolet protective agent containing a combination of core-shell type inorganic nanoparticles and an organic ultraviolet absorber, and a laminate having an ultraviolet protective layer using the same.

Nanoparticles of inorganic materials such as metal oxides include those having various functionalities. For example, nanoparticles of zinc oxide (ZnO) and titanium dioxide (TiO ₂ ) are known to be useful for UV protection at wavelengths up to about 360 nm. For example, in Patent Document 1, an ultraviolet shielding coating composition containing composite zinc oxide fine particles in which the surface of zinc oxide fine particles is coated with at least one selected from oxides and hydroxides of Al, Si, Zr and Sn. Has been proposed. Further, it is known that some organic ultraviolet absorbers such as hydroxyphenyltriazine can absorb ultraviolet rays having a relatively long wavelength (up to about 400 nm).

Japanese Unexamined Patent Publication No. 2010-261712

In one aspect, the present disclosure relates to UV protection agents comprising a combination of core-shell inorganic nanoparticles and an organic UV absorber. The core-shell type inorganic nanoparticles have a core portion containing zinc oxide or titanium oxide, and a shell portion containing silicon dioxide (silica). In another aspect, the present disclosure relates to a laminate having a substrate and a UV protection layer. The UV protection layer contains core-shell type inorganic nanoparticles, an organic UV absorber, and a binder, and the core-shell type inorganic nanoparticles have a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide. ..

The present disclosure provides an ultraviolet protective agent that can protect against ultraviolet rays having a relatively long wavelength, but does not yellow the added object. By using the ultraviolet protective agent, it is possible to provide an ultraviolet protective layer capable of protecting ultraviolet rays having a relatively long wavelength.

It is a light transmission spectrum of Example 3 using Tinuvin 477, Comparative Example 1-2 and Comparative Example 2-3, and Comparative Example 3-1 using only silica-coated ZnO. 7 is a light transmission spectrum of Example 7 using Uvinul 3050, Proportional 1-5 and Comparative Example 2-6, and Comparative Example 3-1 using only silica-coated ZnO. It is a graph which ^shows the transition of b * when only an organic UV absorber is used, and when uncoated ZnO or silica-coated ZnO is added thereto.

(Technical background of the present disclosure)
Although nanoparticles of zinc oxide (ZnO) and titanium dioxide (TiO ₂ ) are known to be useful for UV protection at wavelengths up to about 360 nm, they have photocatalytic activity and therefore UV protection during coating. When blended as an agent, it has the disadvantage of reducing the weather resistance of the coating. On the other hand, in the field of ultraviolet protection agents, there is a demand for a material capable of dealing with ultraviolet rays having a relatively long wavelength (up to about 400 nm), which is close to the visible light region. Some organic UV absorbers, including hydroxyphenyltriazine and the like, can absorb UV light of relatively long wavelengths, but such organic UV absorbers, for example, when added to a coating, cause the coating to turn yellow. Often ends up. The present disclosure provides a means for solving such problems.

(UV protection agent)
The core-shell type inorganic nanoparticles contained in the UV protection agent of the present disclosure are nanoparticles composed of substantially an inorganic material, having at least a core portion and a shell portion covering the core portion. In addition, in this specification, "substantially" means, for example, occupying 85% by weight or more, 90% by weight or more, 95% by weight or more, or 98% by weight or more of the whole. In one embodiment, the average particle size of the core-shell type inorganic nanoparticles is 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less, and is 10 nm or more, 20 nm or more, 30 nm or more, 40 nm. Above, or 50 nm or more, for example, 10 nm to 400 nm range, 10 nm to 350 nm range, 10 nm to 300 nm range, 10 nm to 250 nm range, 10 nm to 200 nm range, 10 nm to 150 nm range, or 10 nm to 100 nm. Is the range of. The average particle size of the core-shell type inorganic nanoparticles can be specified, for example, by measuring 500 to 1000 particles using a transmission electron microscope (TEM) and obtaining the average thereof.

The core portion of the core-shell type inorganic nanoparticles contains zinc oxide (ZnO) or titanium oxide (TiO ₂ ). The core portion may be substantially composed of zinc oxide or titanium oxide, or may be composed only of zinc oxide or titanium oxide. The core portion may be a mixture of zinc oxide and titanium oxide, or a composite metal oxide containing zinc and titanium. In one embodiment, the average diameter of the core portion is 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, or 50 nm or more and 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or It is 100 nm or less. Specifically, for example, it is in the range of 25 nm to 100 nm, 25 nm to 80 nm, 50 nm to 80 nm, or 60 nm to 80 nm. The average diameter of the core portion is considered to be substantially the same as the average diameter of the nanoparticles before forming the shell portion.

The shell portion of the core-shell type inorganic nanoparticles _{contains silicon dioxide (silica, SiO 2} ). The shell portion may be substantially composed of silicon dioxide, or may be composed of only silicon dioxide. The shell portion does not have to cover the entire surface of the core portion, for example, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85 of the surface area of the core portion. It may cover% or more, 90% or more, or 95% or more. In one embodiment, the average thickness of the shell portion is 3 nm or more, 4 nm or more, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, or 50 nm or more. Specifically, for example, it is in the range of 2 nm to 50 nm, 2 nm to 25 nm, or 2 nm to 10 nm. The thickness of the shell portion and the like can be measured using, for example, a transmission electron microscope (TEM).

The core-shell type inorganic nanoparticles can be prepared, for example, by treating metal oxide nanoparticles containing zinc oxide or titanium oxide with a silicic acid compound to form a shell portion. In one aspect, the present disclosure relates to a method for producing core-shell type inorganic nanoparticles for use as a UV protection agent in combination with an organic UV absorber. Examples of the silicic acid compound include orthosilicate esters such as tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMS). To form the shell portion, for example, an aqueous solvent containing water, methanol, ethanol, etc. is prepared, metal oxide nanoparticles are added thereto and dispersed, and a silicic acid compound is further added thereto, and the shell portion is formed under high temperature and high pressure (for example, 140). It can be carried out by reacting at ° C. or higher and 30 atm or higher for 2 to 3 hours or longer.

It is preferable to modify the metal oxide nanoparticles with amino acids in advance because the shell portion can be efficiently formed. As the amino acids used for modification, amino acids having an aminoalkyl group are preferable. The aminoalkyl group preferably has a primary amino group at the terminal. The aminoalkyl group preferably has 3 or more or 4 or more carbon atoms in the alkyl chain. Preferred aminoalkyl groups include aminopropyl groups, aminobutyl groups, aminopentyl groups, and aminohexyl groups. Preferred amino acids include lysine (L-lysine or D-lysine). To modify the metal oxide nanoparticles, add amino acids to a solution obtained by dispersing the nanoparticles in an aqueous solvent containing, for example, water, methanol or ethanol, and at 50 to 60 ° C. under normal pressure (1 atm). This can be done by stirring for 12 hours or more. Therefore, in one embodiment, the core-shell type inorganic nanoparticles contain amino acids such as lysine, or derivatives or decomposition products thereof, at least between the core portion and the shell portion, or in the shell portion.

The core-shell type inorganic nanoparticles may be further modified with a silane coupling agent after forming the shell portion. By modifying the surface of the shell portion with a silane coupling agent, for example, when mixed with a coating composition, a binder (for example, acrylic resin, urethane resin, epoxy resin, phenol resin, and (poly) vinyl alcohol) Affinity with other components such as, etc. may be improved, and the haze of the formed coating may be reduced. The amount of the silane coupling agent used for the modification is preferably such that the surface of the nanoparticles is substantially covered with a single layer. The amount of such a silane coupling agent can be calculated based on the specific surface area of the nanoparticles and the area that the silane coupling agent can cover per unit amount, eg, 0 relative to the weight of the nanoparticles. It ranges from 5 to 40% by weight, 0.5 to 20% by weight, 0.5 to 10% by weight, 0.5 to 5% by weight, or 0.5 to 2% by weight. Examples of silane coupling agents include 3-methacryloxypropyltrimethoxysilane (available under the trade name "SILQUEST A-174"), isooctylrimethoxysilane, N- (3-triethoxysilylpropyl) methoxyethoxyethoxy. Ethyl carbamate, polyalkylene oxide alkoxysilane (available under the trade name "SILQUEST A1230"), N- (3-triethoxysilylpropyl) methoxyethoxyethoxyethyl carbamate, 3- (methacryloyloxy) propyltrimethoxysilane, 3-( Acryloxypropyl) trimethoxysilane, 3- (methacryloyloxy) propyltriethoxysilane, 3- (methacryloyloxy) propylmethyldimethoxysilane, 3- (acryloyloxypropyl) methyldimethoxysilane, 3- (methacryloyloxy) propyldimethylethoxy Silane, 3- (methacryloyloxy) propyldimethylethoxysilane, vinyldimethylethoxysilane, phenyltrimethoxysilane, n-octyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, Vinylmethyldiacetoxysilane, vinylmethyldiethoxysilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltri-t-butoxysilane, vinyltris-isobutoxysilane , Vinyltriisopropenoxysilane, vinyltris (2-methoxyethoxy) silane, styrylethyltrimethoxysilane, mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like.

Any commercially available organic UV absorber to be combined with the core-shell type inorganic nanoparticles can be used. Examples of organic UV absorbers include hydroxyphenyltriazine (HPT) -based ones (eg, commercially available from BASF under trade names such as Tinuvin 400, Tinuvin 405, Tinuvin 460, Tinuvin 477, Tinuvin 479), benzotriazoles. (BTZ) -based products (eg, commercially available from BASF under trade names such as Tinuvin PS, Tinuvin 99-2, Tinuvin 326, Tinuvin 384-2, Tinuvin 900, Tinuvin 928, Tinuvin 970, Tinuvin 1130), cyano Acrylate-based products (for example, commercially available from BASF under trade names such as Uvinul 3035, Uvnul 3039, Uvinul 3030), benzophenone-based products (for example, Uvinul 3049, Uvinul 3050, Chimassorb 81, etc., commercially available from BASF). (Commercially available) and the like. In one embodiment, the organic ultraviolet absorber preferably has a maximum absorption wavelength in the range of 340 nm to 360 nm from the viewpoint of sufficiently obtaining a synergistic effect when combined with the core-shell type inorganic nanoparticles. In another embodiment, the organic ultraviolet absorber is preferably a compound having two or more, or three or more, phenolic hydroxyl groups, which are hydroxyl groups bonded to aromatic hydrocarbons, in one molecule. Examples of such organic UV absorbers include Tinuvin 477, Tinuvin 384-2, Tinuvin 571, and Uvinul 3050. The combination of the core-shell type inorganic nanoparticles and the organic ultraviolet absorber can be carried out by simply mixing the two under normal temperature and pressure.

Organic UV absorbers may appear yellow to the naked eye depending on their absorption properties. Further, when an organic ultraviolet absorber and untreated metal oxide nanoparticles (ZnO, TiO _2, etc.) are mixed in order to expand the band of ultraviolet rays that can be protected, the yellowish color becomes stronger. However, when the core-shell type inorganic nanoparticles of the present disclosure are used instead of the untreated metal oxide nanoparticles, an ultraviolet protective agent capable of protecting ultraviolet rays in a wider band while suppressing the yellowing can be obtained. Can be provided.

(Laminated body)
The laminate of the present disclosure has at least a base material and a UV protection layer. The UV protection layer contains at least core-shell type inorganic nanoparticles, an organic UV absorber, and a binder. The UV protection layer also imparts known additives such as anti-fog agents, antistatic agents, anti-fingerprint agents, anti-oil agents, anti-lint agents, antifouling agents and other easy-to-cleaning agents, or easy-to-cleaning functions. Other agents, or combinations thereof, may be further included. The UV protection layer may be in contact with the surface of the base material, but a functional layer such as a primer layer may be present between the base material and the UV protection layer. The UV protection layer is provided on at least one main surface side of the base material, and may be provided on both sides of two opposing main surfaces of the base material in some cases. Alternatively, an adhesive layer may be provided on the UV protection layer or on the main surface of the base material opposite to the UV protection layer. The adhesive layer may contain any known adhesive such as an acrylic adhesive, a urethane adhesive, a silicone adhesive, a polyester adhesive, and a rubber adhesive. The thickness of the UV protection layer is, for example, 0.08 μm or more, 0.2 μm or more, or 1 μm or more, and is 30 μm or less, 20 μm or less, or 10 μm or less, for example, 0.08 μm to 30 μm, 0.08 μm to 20 μm, or It can be in the range of 0.08 to 10 μm. Since the UV protection layer contains core-shell type inorganic nanoparticles, it has a higher hardness than that without it. The hardness can be evaluated by performing a wear test using, for example, steel wool and measuring the change in haze before and after the test.

The UV protection layer is preferably colorless, transparent, or colorless and transparent. The optical aspect of the UV protection layer can be characterized by ^{, for example, the chromaticity b * or haze in the Lab color system.} In one embodiment, the colorless UV protection layer has a chromaticity b ^* in the Lab color system of 4.0 or less, 3.9 or less, 3.8 or less, 3.7 or less, 3.6 or less, 3 5.5 or less, 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or less, 1.0 or less, or 0.5 or less. ^{Further, the chromaticity b *} in the Lab color system of the UV protection layer is higher than ^{the chromaticity b * of} the layer formed in the same manner except that zinc oxide or titanium oxide nanoparticles are used instead of the core-shell type inorganic nanoparticles. Low. Although not bound by theory, this is thought to be due to the yellowing suppression effect of the shell portion of the core-shell type inorganic nanoparticles. In one embodiment, the transparent UV protection layer has a haze of 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less. , 3.0% or less, or 2.5% or less. Haze can be measured using a haze meter according to JIS K 7361-1 and JIS K 7136. When the surface of the shell portion of the core-shell type inorganic nanoparticles is modified with a silane coupling agent, the haze of the UV protection layer using the silane coupling agent tends to be low.

In a preferred embodiment, the transmittance of the UV protection layer at a wavelength of 380 nm is 35% or less, 33% or less, 30% or less, 29% or less, 28% or less, 27% or less, 26% or less, 25% or less, or 20. % Or less. In another embodiment, the wavelength at which the UV protection layer has a transmittance of 20% is in the range of 370 nm to 400 nm, or 380 nm to 400 nm. In another embodiment, the wavelength at which the UV protection layer has a transmittance of 10% is in the range of 370 nm to 400 nm, or 380 nm to 400 nm. In another embodiment, the wavelength at which the UV protection layer has a transmittance of 5% is in the range of 370 nm to 400 nm, or 380 nm to 400 nm. The UV protection layer having such characteristics can protect UV rays having a relatively long wavelength close to the visible light region. The UV protection layer of the present disclosure does not transmit substantially all light having a wavelength shorter than a certain range. Further, in another embodiment, the transmittance of the UV protection layer at a wavelength of 430 nm is the same as that of the layer formed in the same manner except that zinc oxide or titanium oxide nanoparticles are used instead of the core-shell type inorganic nanoparticles. It is higher than the rate and is 80% or more. Yellowing is suppressed in the UV protection layer having such characteristics. The transmittance can be measured using an ultraviolet-visible spectrophotometer.

In the UV protection layer, the core-shell nanoparticles have 1% by weight or more, 5% by weight or more, 10% by weight or more, and 15% by weight or more with respect to the total weight of the UV protection layer from the viewpoint of obtaining a sufficient UV protection effect. , Or is preferably contained in an amount of 20% by weight or more. In one embodiment, the amount of core-shell type nanoparticles is 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight with respect to the total weight of the ultraviolet protection layer. % Or less, 60% by weight or less, 55% by weight or less, 50% by weight or less, 45% by weight or less, 40% by weight or less, 35% by weight or less, or 30% by weight or less. The range of the amount of core-shell nanoparticles is, for example, 1-90% by weight, 1-50% by weight, 1-45% by weight, 1-40% by weight, 1-35% by weight with respect to the total weight of the UV protection layer. %, Or 1 to 30% by weight. The smaller the amount of core-shell nanoparticles, the lower the haze of the UV protection layer tends to be.

In the UV protection layer, the organic UV absorber is 0.1% by weight or more, 0.25% by weight or more, 0.5% by weight with respect to the total weight of the UV protection layer from the viewpoint of obtaining a sufficient UV protection effect. 0.75% by weight or more, 1% by weight or more, 1.25% by weight or more, 1.5% by weight or more, 2% by weight or more, 2.5% by weight or more, 3% by weight or more, 3.5% by weight As described above, it may be contained in an amount of 4% by weight or more, 4.5% by weight or more, or 5% by weight or more. In one embodiment, the amount of the organic UV absorber is, for example, 25% by weight or less, 20% by weight or less, 15% by weight or less, or 10% by weight or less. The range of the amount of the organic UV absorber is, for example, 0.1 to 25% by weight, 0.1 to 20% by weight, 0.1 to 15% by weight, or 0.1 based on the total weight of the UV protection layer. It is 10% by weight. The smaller the amount of the organic UV absorber, the more the yellowing of the UV protection layer tends to be suppressed. In one embodiment, the ratio of the organic UV absorber to the coreshell nanoparticles in the UV protection layer is the weight of the organic UV absorber / coreshell nanoparticles from the viewpoint of the balance between the UV protection performance and the optical properties of the UV protection layer. The ratio is 0.01 or more, 0.05 or more, 0.1 or more, 0.15 or more, or 0.2 or more, 0.5 or less, 0.45 or less, 0.4 or less, 0.35 or less. , Or 0.3 or less, for example, in the range of 0.01 to 0.5, or in the range of 0.01 to 0.4.

In one aspect, the present disclosure relates to a method of forming a UV protection layer, comprising applying a coating precursor containing at least a core-shell inorganic nanoparticles, an organic UV absorber, and a binder. The UV protection layer can be formed by applying a coating precursor containing at least a core-shell type inorganic nanoparticles, an organic UV absorber, and a binder to the substrate. The coating precursor may or may not contain an organic solvent, depending on the constituents. The coating precursor can be applied by known coating methods such as bar coating, dip coating, spin coating, capillary coating, spray coating, gravure coating, or screen printing, or a combination thereof. The applied coating precursor can be cured by a known polymerization method such as ultraviolet (UV) polymerization or thermal polymerization.

As the binder, for example, a UV curable acrylate resin or a thermosetting acrylate resin can be used. Specific examples of the binder include acrylic resin, urethane resin, epoxy resin, phenol resin, and (poly) vinyl alcohol. More specifically, dipentaerythritol pentaacrylate ("SR399", Sartomer), pentaerythritol triacrylate isophorone diisocyanate (IPDI, "UX5000" Japanese chemical), urethane acrylate (eg, "UV1700B" and "UB6300B", Japan Synthetic Chemical Industry, or "EBECRYL8301" and "KRM8528", Allnex), trimethylhydroxyldiisocyanate / hydroxyethyl acrylate (TMHDI / HEA, "EB4858", Daicel Cytec), polyethylene oxide (PEO) modified bis-A diacrylate ("R551") , Nippon Kayaku), PEO-modified bis-A epoxy acrylate ("3002M", Kyoeisha Chemical Co., Ltd.), silane-based UV curable resin ("SK501M", Nagasechemtex), and 2-phenoxyethyl methacrylate ("SR340", Sartomer); as well as mixtures thereof. The binder is 5% by weight or more, 10% by weight or more, 15% by weight or more, or 20% by weight or more, and 99% by weight or less, 95% by weight or less, based on the total weight of the cured ultraviolet protective layer. , 90% by weight or less, 75% by weight or less, 60% by weight or less, 50% by weight or less, or 40% by weight or less, for example, 95% by weight to 5% by weight, 90% by weight to 10% by weight, 75% by weight. It may be included in the range of% -10% by weight, 60% by weight to 10% by weight, 50% by weight to 10% by weight, or 40% by weight to 20% by weight.

In some embodiments, the coating precursor for forming the UV protection layer may further include a cross-linking agent as an optional component. Examples of cross-linking agents include (a) di (meth) acrylic-containing compounds, such as 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,6. -Hexanediol monoacrylate monomethacrylate, ethylene glycol diacrylate, alkoxylated aliphatic diacrylate, alkoxylated cyclohexanedimethanol diacrylate, alkoxylated hexanediol diacrylate, alkoxylated neopentyl glycol diacrylate, caprolactone-modified neopentyl glycol hydroxypi Valate diacrylate, caprolactone-modified neopentyl glycol hydroxypivalate diacrylate, cyclohexanedimethanol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, ethoxylated (10) bisphenol A diacrylate, ethoxylated (3) bisphenol A diacrylate , Ethanolylated (30) bisphenol A diacrylate, ethoxylated (4) bisphenol A diacrylate, hydroxypivalaldehyde-modified trimethylolpropane diacrylate, neopentyldiacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) Diacrylate, polyethylene glycol (600) diacrylate, propoxylated neopentyl glycol diacrylate, tetraethylene glycol diacrylate, tricyclodecanedimethanol diacrylate, triethylene glycol diacrylate, trimethylolpropylene diacrylate; (b) Tri (b) Meta) Acrylic-containing compounds such as glycerol triacrylate, trimethylolpropane triacrylate, ethoxylated triacrylate (eg, ethoxylated (3) trimethylolpropane triacrylate, ethoxylated (6) trimethylolpropane triacrylate, ethoxylated (eg) 9) Trimethylolpropane triacrylate, ethoxylated (20) trimethylolpropane triacrylate), pentaerythritol triacrylate, propoxylated triacrylate (eg, propoxylated (3) glyceryl triacrylate, propoxylated (5.5) ) Glyceryl triacrylate, propoxylated (3) Trimethylolpropa Antiacrylate, propoxylated (6) trimethylolpropan triacrylate), trimethylolpropan triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate; (c) highly functional (meth) acrylic-containing compound, such as ditri. Methylolpropantetraacrylate, dipentaerythritol pentaacrylate, ethoxylated (4) pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, caprolactone-modified dipentaerythritol hexaacrylate; (d) oligomeric (meth) acrylic compound, such as urethane acrylate, Poly (meth) acrylic monomers selected from the group consisting of polyester acrylates, epoxy acrylates; the polyacrylamide analogs described above; and combinations thereof. Exemplary commercially available cross-linking agents include trimethylolpropane triacrylate (TMPTA, "SR351", Sartomer), pentaerythritol tri / tetraacrylate (PETA, "SR444" or "SR295", Sartomer), and pentaerythritol pentaacrylate. ("SR399", Sartomer). Further, a mixture of polyfunctional and hypofunctional acrylates, for example, a mixture of PETA and phenoxyethyl acrylate (PEA) may be used.

The base material contained in the laminate of the present disclosure is not particularly limited, and examples thereof include a film, a polymer plate, a sheet glass, and a metal sheet. The base material may be provided with a design layer on its surface, or may be transparent. Examples of films include polycarbonate, poly (meth) acrylate (eg, polymethylmethacrylate (PMMA)), polyolefin (eg, polypropylene (PP)), polyurethane, polyester (eg, polyethylene terephthalate (PET)), polyamide, polyimide. , Phenolic resin, cellulose diacetate, cellulose triacetate, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile butadiene styrene copolymer (ABS), epoxy, polyethylene, polypropylene and vinyl chloride, or films made from glass. Examples of polymer plates are made from polycarbonate (PC), polymethylmethacrylate (PMMA), styrene-acrylonitrile copolymer, acrylonitrile butadiene styrene copolymer (ABS), a blend of PC and PMMA, or a laminate of PC and PMMA. Can be mentioned. The metal sheet may be flexible or rigid. As used herein, "flexible metal sheet" refers to a metal sheet that can withstand mechanical stresses such as bending or stretching without significant irreversible changes, and "hard metal sheet" refers to a significant irreversible. A metal sheet that cannot withstand mechanical stress such as bending or stretching without a change. Examples of flexible metal sheets include those made of aluminum. Examples of hard metal sheets include those made of aluminum, nickel, nickel chrome, and stainless steel. Typical thicknesses of film substrates range from about 5 micrometers to about 500 micrometers. Typical thicknesses of polymer plate substrates are from about 0.5 mm to about 10 mm, from about 0.5 mm to about 5 mm, or from about 0.5 mm to about 3 mm. Typical thicknesses of sheet glass or metal sheet substrates are from about 5 μm to about 500 μm, from about 5 μm to about 100 μm, from 5 μm to about 50 μm, or from about 5 μm to about 30 μm.

The UV protection layer according to the present disclosure containing a combination of core-shell type inorganic nanoparticles and an organic UV absorber is useful as a coating for various products for which it is desirable to protect against UV rays. Examples of such products include home appliances such as vacuum cleaners and washing machines, interior materials such as furniture and wallpaper, exterior materials such as paint substitute films, optical displays, lenses, mirrors, mobile phones, window films, and solar panels. , And goggles. In particular, the UV protection layer according to the present disclosure is useful in applications such as optical displays and window films where a colorless and transparent UV protection coating is required.

The present disclosure includes the following embodiments.
(1) A laminate having a base material and an ultraviolet protection layer, which is a laminate.
The UV protection layer contains core-shell type inorganic nanoparticles, an organic UV absorber, and a binder.
The core-shell type inorganic nanoparticles are a laminate having a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide.
^{(2) The chromaticity b *} of the UV protection layer in the Lab color system is the same except that zinc oxide or titanium oxide nanoparticles are used instead of the core-shell type inorganic nanoparticles. ^* The laminate according to (1), which is lower than.
(3) The laminate according to (1) or (2), wherein the organic ultraviolet absorber contains a compound having two or more phenolic hydroxyl groups in one molecule.
(4) The laminate according to any one of (1) to (3), wherein the core-shell type inorganic nanoparticles contain at least lysine or a derivative or decomposition product thereof between the core portion and the shell portion.
(5) The laminate according to any one of (1) to (4), wherein the weight ratio of the organic UV absorber / core-shell type inorganic nanoparticles in the UV protection layer is in the range of 0.01 to 0.5. body.

(6) The laminate according to any one of (1) to (5), wherein the transmittance of the UV protection layer at a wavelength of 380 nm is lower than that of the similarly formed layer except that the core-shell type inorganic nanoparticles are not used. ..
(7) The laminate according to any one of (1) to (6), wherein the wavelength at which the transmittance of the ultraviolet protective layer is 20% is in the range of 370 nm to 400 nm.
(8) The laminate according to any one of (1) to (7), wherein the surface of the shell portion of the core-shell type inorganic nanoparticles is modified with a silane coupling agent.
(9) A coating precursor for forming an ultraviolet protective coating, which is a coating precursor.
Contains core-shell type inorganic nanoparticles, an organic UV absorber, and a binder.
The core-shell type inorganic nanoparticles are a coating precursor having a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide.
(10) The core-shell type inorganic nanoparticles include a combination of core-shell type inorganic nanoparticles and an organic ultraviolet absorber, and the core-shell type inorganic nanoparticles have a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide. An ultraviolet protective agent containing lysine or a derivative or decomposition product thereof at least between the core portion and the shell portion.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Preparation Example 1)
(1) Preparation of L-lysine-modified ZnO sol (Sol-1)
Add 0.0365 g of L-lysine (Fuji Film Wako Pure Chemical Industries, Ltd.) to a mixture of 10 g of ZnO sol (AQ-E3913, diameter 100 nm, Reginocolor Industries), 25.2 g of methanol, and 4.8 g of distilled water. It was. After stirring at room temperature for 10 minutes, the mixture was stirred in an oil bath at 60 ° C. for 16 hours to obtain an L-lysine-modified ZnO sol (Sol-1).

(2) Preparation of silica-coated ZnO sol (Sol-3)
5.2 g of tetraethyl orthosilicate (TEOS, Wako Pure Chemical Industries, Ltd.) was added to Sol-1. After stirring at room temperature for 10 minutes, the mixture was transferred to an autoclave and heated at 140 ° C. for 5 hours to obtain Sol-2. The water and methanol of Sol-2 were then removed using a rotary evaporator to a solid content of approximately 20% by weight. The procedure of adding 1-methoxy-2-propanol and further removing the remaining water and methanol was repeated twice. As a result, a silica-coated ZnO sol (Sol-3) having a silica-coated ZnO particle content of 20% by weight in 1-methoxy-2-propanol was obtained.

(3) Preparation of Silane Coupling Agent Modified Silica Coated ZnO Sol (Sol-4)
0.2235 g of silane coupling agent ("SILQUEST A-174", 3-methacryloxypropyltrimethoxysilane, Momentive) and 0.0125 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1- Oxil (“TEMPOB”, 5 wt%, Aldrich) was added to 90.4 g of Sol-2, stirred at room temperature for 10 minutes and then heated in an oven at 60 ° C. for 16 hours. Water and methanol were then removed using a rotary evaporator to bring the solids content to approximately 20% by weight. The procedure of adding 20 g of 1-methoxy-2-propanol and further removing the remaining water and ethanol was repeated twice. As a result, a silane coupling agent-modified silica-coated ZnO sol (Sol-4) having a ZnO nanoparticles content of 20% by weight in 1-methoxy-2-propanol was obtained.

(4) Preparation of uncoated ZnO sol (Sol-5)
20 g of ZnO sol (AQ-E3913, diameter 96 nm, Reginocolor Industries) and 22.5 g of 1-methoxy-2-propanol were mixed at room temperature for 10 minutes. Using a rotary evaporator, the procedure of adding 20 g of 1-methoxy-2-propanol and removing water was repeated twice. As a result, an uncoated ZnO sol (Sol-5) having a ZnO nanoparticle content of 20% by weight in 1-methoxy-2-propanol was obtained.

(5) Preparation of hybrid UV absorber Various organic UV absorbers are mixed with any of Sol-3, Sol-4 or Sol-5 and stirred at room temperature for 1 hour to obtain a hybrid UV absorber. It was. The organic UV absorbers used are as follows.
"Tinuvin 477": hydroxyphenyltriazine-based UV absorber, maximum absorption wavelength 356 nm, BASF
"Tinuvin 384-2": Benzotriazole-based UV absorber, maximum absorption wavelength 345 nm, BASF
"Tinuvin 571": Benzotriazole-based UV absorber, maximum absorption wavelength 343 nm, BASF
"Uvinul 3050": cyanoacrylate-based UV absorber, maximum absorption wavelength of about 345 nm, BASF

(6) Preparation of coating precursor Any of an organic UV absorber, Sol-3 or Sol-5, or a hybrid UV absorber is mixed with a binder (aliphatic urethane acrylate) and contained in 1-methoxy-2-propanol. , The solid content was adjusted to be 40% by weight. Next, 0.002 g of silicone polyether acrylate (TEGO Rad 2250, Evonik) and 0.06 g of ESACURE ONE (photoinitiator, Lamberti) were added to obtain a coating precursor.

(7) Application of coating The coating precursor was applied on a PET substrate (A4100, Toyobo) having a thickness of 50 μm using Mayer rod # 20, and dried in an oven at 60 ° C. for 10 minutes. The coating thickness was 9 μm in the dry state. The coating was then cured by UV irradiation to give a sample.

(8) Sample evaluation b ^* , haze, and transmittance were measured for the coated sample. b ^* was measured using a spectrophotometer (CM-3600d, Konica Minolta). The haze was measured using a haze meter (NDH5000W, Nippon Denshoku Kogyo) according to JIS K 7361-1 and JIS K 7136. The transmittance was measured using an ultraviolet-visible spectrophotometer (U-4100, Hitachi High-Technologies Corporation). The results are summarized in Tables 1 and 2. The light transmission spectra of Example 3 using Tinuvin 477, Comparative Examples 1-2 and 2-3, and Comparative Example 3-1 using only silica-coated ZnO are shown in FIG. The light transmission spectra of Example 7 using Uvinul 3050, Proportional 1-5 and Comparative Example 2-6, and Comparative Example 3-1 using only silica-coated ZnO are shown in FIG. FIG. 3 shows a graph showing the transition ^{of b *} when only the organic UV absorber is used and when uncoated ZnO or silica-coated ZnO is added thereto.

(Preparation Example 2)
(1) Preparation of L-lysine-modified TiO ₂ sol (Sol-1)
0.0475 g of L-lysine (Fuji Film Wako Pure Chemical Industries, _{Ltd.) was added to 10 g of TiO 2} sol (Reginocolor Industries), 25.48 g of methanol, and 4.52 g of a mixture. After stirring at room temperature for 10 minutes, the mixture was stirred in an oil bath at 60 ° C. for 16 hours _{to obtain an L-lysine-modified TiO 2} sol (Sol-1).

(2) Preparation of silica-coated TiO ₂ sol (Sol-2)
5.98 g of tetraethyl orthosilicate (TEOS, Wako Pure Chemical Industries, Ltd.) was added to Sol-1. After stirring at room temperature for 10 minutes, the mixture was transferred to an autoclave and heated at 150 ° C. for 6 hours to obtain Sol-2. The water and methanol of Sol-2 were then removed using a rotary evaporator to a solid content of approximately 20% by weight. The procedure of adding 1-methoxy-2-propanol and further removing the remaining water and methanol was repeated twice. _{As a result, a silica-coated TiO 2} sol (Sol-3) having _{a silica-coated TiO 2} particle content of 20% by weight in 1-methoxy-2-propanol was obtained.

(3) _{Preparation of uncoated TiO 2} sol (Sol-3)
20 g of TiO ₂ sol (Reginocolor Industries) and 22.5 g of 1-methoxy-2-propanol were mixed at room temperature for 10 minutes. Using a rotary evaporator, the procedure of adding 20 g of 1-methoxy-2-propanol and removing water was repeated twice. _{As a result, an uncoated TiO 2} sol (Sol-3) having _{a TiO 2} nanoparticle content of 20% by weight in 1-methoxy-2-propanol was obtained.

(4) Preparation of Hybrid UV Absorbent An organic UV absorber (Tinuvin477) and either Sol-2 or Sol-3 were mixed and stirred at room temperature for 1 hour to obtain a hybrid UV absorber.

(5) Preparation and Evaluation of Sample A coated sample was prepared in the same manner as in the procedures (6) to (8) of Preparation Example 1 ^{, and b *} , haze, and transmittance were measured. The results are summarized in Table 3.

Claims (10)

A laminate having a base material and an ultraviolet protection layer,
The UV protection layer contains core-shell type inorganic nanoparticles, an organic UV absorber, and a binder.
The core-shell type inorganic nanoparticles are a laminate having a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide. Chromaticity b ^* in the Lab color system of the UV protective layer, wherein the core-shell except for using the inorganic nanoparticles nanoparticles zinc oxide or titanium oxide in place of similarly-formed than chromaticity b ^* layer The low laminate according to claim 1. The laminate according to claim 1 or 2, wherein the organic ultraviolet absorber contains a compound having two or more phenolic hydroxyl groups in one molecule. The laminate according to any one of claims 1 to 3, wherein the core-shell type inorganic nanoparticles contain at least lysine or a derivative or decomposition product thereof between the core portion and the shell portion. The laminate according to any one of claims 1 to 4, wherein the weight ratio of the organic ultraviolet absorber / core-shell type inorganic nanoparticles in the ultraviolet protection layer is in the range of 0.01 to 0.5. The laminate according to any one of claims 1 to 5, wherein the ultraviolet protective layer has a lower transmittance at a wavelength of 380 nm than a layer similarly formed except that the core-shell type inorganic nanoparticles are not used. The laminate according to any one of claims 1 to 6, wherein the wavelength at which the transmittance of the ultraviolet protective layer is 20% is in the range of 370 nm to 400 nm. The laminate according to any one of claims 1 to 7, wherein the surface of the shell portion of the core-shell type inorganic nanoparticles is modified with a silane coupling agent. A coating precursor for forming UV protection coatings,
Contains core-shell type inorganic nanoparticles, an organic UV absorber, and a binder.
The core-shell type inorganic nanoparticles are a coating precursor having a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide. The core-shell type inorganic nanoparticles include a combination of core-shell type inorganic nanoparticles and an organic ultraviolet absorber, and the core-shell type inorganic nanoparticles have a core portion containing zinc oxide or titanium oxide and a shell portion containing silicon dioxide, and at least the core portion. A UV protection agent containing ricin or a derivative or decomposition product thereof between the shell portion and the shell portion.

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